Laserfiche WebLink
<br />METHODS <br />Four transects were surveyed perpendicular to the channel. <br />Data from three of these transects are presented here. The <br />transects were subdivided into "cells" based on geomorphic <br />features such as channel, flood plain, and terrace. Transect 2 <br />is within the area of active mining; Transects 3 and 1 are <br />located on either side of the main mining activity. Transect 4 <br />is located approximately 1.25 mi (2 lan) upstream of the sand <br />mining, serving as a control. Groundwater wells along each <br />transect have been monitored at least monthly since August <br />1990. F~ach individual tree within a 150 m belt, centered on <br />the transects, has been tagged for ongoing monitoring of <br />basal increment, vigor and mortality. Tree crown vigor was <br />surveyed on a tree-by-tree basis before and after mining (8/91 <br />and 8/92) and was measured as the percentage of crown <br />volume of each tree that was filled by leaves and branches. <br />